Screw driver



L. MULLER SCREW DRIVER June 27, 1933.

Filed Oct. 14, 1951 Patented June 27, 1933 STATES PATENT OFFECE ouis MfILLER, or Tmcmmmm WURTEMBERQGERMANY, ASSIGNOR T 1 I one A ninennor STUTTGART, GERMAN Application filed Oct0ber '14, 1931, Serial No.

My invention relatesto screw drivers. It,

is anobject of my invention to improve a screw driver: in such manner that the operatwhich after the edge of thescrew driver has been introduced into the groove of the screw head, the movable-shaft halves of the driver head are resiliently spread apart, so that they are applied-against the sidewallsof the screw head groove and secure :the screwv onthe screwdriver. I

InYa preferred embodiment of my inven tion themovablehalf 0f the screw driver is formedas: a two armed crank lever having lgsfsomewhatout ofalignment and being pivoted with its knee on thefixed'half of the screwishaft. "The forward leg of the movable half is tapered so'asto form together with the similarly tapered forward end of the fixed half a-comnlete screw driver head. The rearward legof the movable half carries a slidable sleeve by which the movable halfis controlled. I

V In thef drawing affixed to this specification and forming part thereof, two embodiments of my invention are illustrated diagrammatically by way of example.

In the drawing, v r l is aside elevatiom partly in section, of one embodiment of my invention. v Fig. 23s a side elevation shown in another posi en- L Fig. 3 isa side elevationpartly in section of another, embodiment, and.

\.Fig--t.is' a section on the .line AB- in Fig.3... r

"" ,Fig. ,5 vis a side, elevation partly-in section driver head, the recess 12 will engageith'e in- SQREW DR E 568,756, and in Germany February 10,1931;

inFigQ3.

Referring to the drawing and first to Figs." 1 and 2, 1 is-the screw driver'hand1e,'2 is:=, the fixed shaft the forward portion 3 "of which is reduced so as to 'form one half of 1 the total shaft and head; 4'is =the -movablel shaft pivotally secured to the forwardhpor-f tion 3 of the fixed shaft 2 byimeans of-atr ans verse pin 5 and a fixed sleeve 6 surrounding both halves. The plane .zin whichzthe com, posite shaft is subdivided is parallel-to and"? coincides with the free edge of thezscre'wi driver so thatthe driver head is'formed by the tapered end portions'3" and 4 ofthe halves 3 and 4 supplementing each other to form the full head and edge. The rearward leg .7 of the movable ha'1f4 is bent slightly. outwardly, so that the movable :half formsacrank lever, the rearward leg of which can be used as actuating lever arm for spreading; the halves 3 and 4 of'the head. 78 is a'leaf. s'pring' inserted between the rearward leg 71 of the movable shaft and the fixed shaft: and? acting on the movable shaft so'as toiforce'mi the head portions 3 and 4' towards each ofth- --v er,'as shown in Fig. 1. 9 is a guide pin secured to the fixed shaft 3' and extending. through recesses provided in the leaf spring 8 and the movable shaft 4, this pin prevent-- ing undesirable transverse displacements of the'movable shaft..- I

10 is a slidable' sleeve adapted to engage the free end of the rearward'leg 7 and guidedon a fixed sleeve 11 secured'on the fixed shaft portion 2. Sleeve 10 is provided with a-coni7 cal recess 12at its forward end.- When sleeve 10 is moved in the direction towards the screw,

of a modification of the embodiment shown clined end portion 13 of the rearward leg 7 of the movable shaft 4, thereby rocking thelatter from the position shown in Fig. 1 into the position shown in Fig. 2, in which the halves 8 and 4- of the screw driver head are spread apart against'th'e action of the spring In the operation of the device the sliding sleeve 10 is moved, after'the screw driver edge has been introduced into the groove of the screw head, so-th'at the halves 3 and 4 of the screw driver head resiliently hold the screw, which is now secured to the screw driver head. The sleeve can be made of insulating material. The two halves of the screw driver shaft and more particularly the rearward leg 7 should be dimensioned in such manner that the halves. 3, and 4 of the head are spread apart in a resilient manner.

Referring now to Figs. 3 and a, showing an embodiment-of myinvention in which the movable shaft is positively actuated by the displacement of the sleeves, the fixed half 3" has a semicircular cross section. The sleeve 10 is provided with a corresponding guide piece 14. The sleeve is provided with another guidepiecepformed by controlling surfaces acting upon the movable shaft and formed with an inner guide face and an outer g-Iride face16. The inner guide face 15 is -formed:by a transverse pin 18 secured to tho ontei-end of the sleeve 10'. When the sleeve 10- ismoved-towards the screw driver head, the outersurface 16 engages the outer semicircular surface 17 of the movable shaft, so

that 'the shaft head is spread apart. The

outer controlling surface 16 is formed by the inner wall of the sleeve 10. When the sleeve 10 is returned into its position of rest, the innor controlling surface 15 formed by the transverse pin-18 engages the inner surface of the rearward end of the movable shaft. The rearward leg'of this shaft is-curved outwardly at 19 near the oint 5, 6 and curved inwardly at 20 near the end of the sleeve 10".

"Referring now to Fig. 5 the sleeve 10 is provided with an extension 21 reaching to the sleeve 6 of the joint and enclosing the latterals well as the curved rearward leg of ,the movable screw driver shaft. The operationof this device is substantially the same as that of the embodiment shown in Fig. 3.

'Iwish it to be understood that I do not desire to limited to the exact details of constructionshown and described for obvious modifications will occur to a. person skilled in the art.

In the claims afiixed to this specification no selection of any particular modification of'the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by these claims is expressly reserved. i

I claim I. A screw holder and driver comprising an edge at its head, a shaft subdivided into a fixed and a movable shaft portion in the central plane of said edge, said movable shaft portion having a front portion tapered on its end so as to form a half of a screw driver head and a rearward leg forming a knee and being somewhat out of alignment with respect to the front portion, said leg being outwardly curved near the knee of said movable portion and inwardly curved near its end, a

pivotal connection connecting the knee of said movable shaft portion with said fixed shaft ortion, a slidable sleeve on said fixed shaft portion and having guiding surfaces engaging the fixed and the movable shaft portions, respectively, and an extensionforming part ofcsa'id slidable 'sleevc. and enclosing said rearward leg and said pivotal connection.

2. A screw holder and driver comprising a handle, shaft- 1in said handlewhich is divided into two "shaft portions in its axial plane, a hinge with its axis extending in parallel to the plane of division connecting the two portions, an edge on the forward end of each portion, and asle eve which is mounted to slide on said shaftbetween said handle and said hinge and is adaptedto act on said shaft portions so asto-mo've their edges apart as it slides toward said hinge,

3. A screw holder and driver, comprising ward end of each portion, and a Isleeve which is 'inoun'ted' to slide on said shaft .between said handleand said hinge-'andis adapted to act on. said shaft portions so as to move their edges apart as it slides toward said hinge.

4. A screw holder and driver comprising a handle, a shaft on said handlewhich divided into two'shaft portions in its axial plane, a hinge with its axis Fextnding in parallel to the plane of divisionlconnecting the two portions, an --edge on the forward end-of each portion, and a sleeve of insulating material which is mounted to slide on said shaft between said handle and-said hinge and is adapted to act onsaid shaft portions so as to move their edges apart as no it slides toward said hinge.-

5. A screw holder and driver comprisinga handle, a shaft on said handle which is divided into two shaft portions in its axialplane, one of said portions being fixed to said shaft, and the other portion being a bell-crank lever,a hinge connecting the lever to said fixed portion, an edge on the forward end of said fixed portion and said lever, and a sleeve which is mounted toslide on said fixed portion between saidhandle and said hinge andisadapted to act onsaid lever so as to move itsedge away from the edge of said fixed portion as it: slides toward said hinge.

6. A screw holder and driver comprising a handle, a shaft on said handle which is divided into two shaft portions in its axial plane, one of said portions being fixed to said shaft. and the other portion being a-bellcrank lever, a beveled face on the end of .85 a handle, a shaft on said handle which-is the rear arm of said lever, a hinge connecting the lever to said fixed portion, an edge on the forward end of said fixed portion and said lever, and a sleeve which is mounted to slide on said fixed portion between said handle and said hinge and is equipped with a camming face for cooperation with the beveled face on said rear arm.

7. A screw holder and driver comprising a handle, a shaft on said handle which is divided into two shaft portions in its axial plane, one of said portions being fixed to said shaft, and the other portion being a bellcrank lever, a hinge connecting the lever to said fixed portion, an edge on the forward end of said fixed portion and said lever, a bush on said fixed portion, and a sleeve which is mounted to slide on said bush and is adapted to act on said lever so as to move its edge away from the edge of said fixed portion as it slides toward said hinge.

8. A screw holder and driver comprising a handle, a shaft on said handle which is divided into two shaft portions in its axial plane, one of said portions being fixed to said shaft, and the other portion being a bellcrank lever, a hinge connecting the lever to said fixed portion, an edge on the forward end of said fixed portion and said lever, a sleeve which is mounted to slide on said fixed portion between said handle and said hinge and is adapted to act on said lever so as to move its edge away from the edge of said fixed portion as it slides toward said hinge, and resilient means tending to return the edge on said lever toward the edge of said fixed position.

In testimony whereof I affix my signature.

4O LOUIS MULLER. 

